Falcon 9 boost as Merlin 1D engine achieves major milestone

SpaceX’s Merlin 1D engine has achieved flight qualification status during its test program at the company’s rocket development facility in McGregor, Texas. An enhanced design to the engines that have flown on the first five Falcon 9 launches, the Merlin 1D will debut on the first Falcon 9 v1.1 launch this summer.

The engines use a propellent fed dual impeller turbo-pump, operating on a gas generator cycle which also provides the high pressure kerosene for the hydraulic actuators, recycling into the low pressure inlet.

The turbo-pump also provides roll control by actuating the turbine exhaust nozzle on the single second stage MVac engine.

“Improved Performance: Thrust increased from 95,000 lbf (sea level) to 140,000 lbf (sea level). Added throttle capability for range from 70-100 percent. Currently, it is necessary to shut off two engines during ascent. The Merlin 1D will make it possible to throttle all engines. Structure was removed from the engine to make it lighter.

Test firings have been ongoing since at least 2011, with the powerpack achieving a full mission duration firing and multiple restarts at target thrust and specific impulse (Isp). During the 2012 series of testing, the engine fired for 185 seconds with 147,000 pounds of thrust, the full duration and power required for a Falcon 9 rocket launch.

Now, in March, 2013, SpaceX announced the completion of a 28 test qualification program, with the Merlin 1D accumulating 1,970 seconds of total test time, the equivalent run time of over 10 full mission durations.

As such, the milestone allows the company to claim the engine is now fully qualified to fly on the Falcon 9 rocket.

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In total, program included four tests at or above the power (147,000 pounds of thrust) and duration (185 seconds) required for a Falcon 9 rocket launch. The Merlin 1D engine was also tested at propellant inlet and operating conditions that were well outside the bounds of expected flight conditions.

“The Merlin 1D successfully performed every test throughout this extremely rigorous qualification program,” said Elon Musk, SpaceX CEO and chief designer. “With flight qualification now complete, we look forward to flying the first Merlin 1D engines on Falcon 9’s Flight 6 this year.”

Notably, from a reliability standpoint, SpaceX’s test program demonstrated a ratio of 4:1 for critical engine life parameters such as firing duration and restart capacity to the engine’s expected flight requirements. This is a much higher ratio that the industry standard of 2:1.

The new engine is designed for improved manufacturability by using higher efficiency processes, increased robotic construction and reduced parts count.

This will be key for several of SpaceX’s future ambitions, not least their upcoming increase in launch frequency, with the next Falcon 9 – the debut of the V1.1 – set to take place in June, carrying Canada’s space weather satellite, CASSIOPE, out of Vandenberg Air Force Base. (*Falcon 9 V1.1 image left is Photoshopped as to what the F9 V1.1 config may look like*)

Focus will then switch to Cape Canaveral, with two satellite missions, the first carrying SES-8, to be followed by the Thaicom 6 launch, scheduled for the summer.

The increase in production has resulted in a busy factory floor at the SpaceX factory in Hawthorne, California, with at least three of the upcoming Falcon 9 v1.1 launch vehicles in an advanced state of production.